Optical module

Abstract

An optical modulator includes: laser diodes disposed in parallel with each other, each laser diode having a different lasing wavelength; optical waveguides disposed in parallel with each other with first ends facing the laser diodes; an optical isolator inserted between the laser diodes and the optical waveguides and attenuating return light reflected from the optical waveguides toward the laser diodes; a lens focusing light emitted from the laser diodes onto the optical waveguides through the optical isolator; an optical switch selecting one of the light beams exiting from the optical waveguides; and an optical modulator modulating the light beam selected by and output from the optical switch.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to an optical module for use in optical communication systems, which serve as infrastructure for the Internet or telephone systems.[0003]2. Background Art[0004]In typical conventional optical modules, the outputs of 12 parallel laser diodes are optically coupled together by an optical coupler. In this case, theoretically, the optical power output from the optical coupler is one-twelfth of the optical power input to the coupler. In order to compensate for this power loss, an optical amplifier is integrated into the module (see, e.g., Furukawa Electric Review, No. 121 (March 2008), pages 1-4). However, the use of such an optical amplifier results in an increase in the power consumption of the optical module. Furthermore, the optical amplifier receives and amplifies unwanted return light reflected within the chip and allows it to reenter the laser diodes. As a result, the widths of the spectra...

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